From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754827AbbGPIsS (ORCPT ); Thu, 16 Jul 2015 04:48:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39336 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754809AbbGPIsN (ORCPT ); Thu, 16 Jul 2015 04:48:13 -0400 From: Baoquan He To: linux-kernel@vger.kernel.org, ncroxon@redhat.com, dyoung@redhat.com, mhuang@redhat.com Cc: Baoquan He Subject: [RHEL6.8 Patch 08/19] vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list Date: Thu, 16 Jul 2015 16:47:06 +0800 Message-Id: <1437036437-25408-12-git-send-email-bhe@redhat.com> In-Reply-To: <1437036437-25408-1-git-send-email-bhe@redhat.com> References: <1437036437-25408-1-git-send-email-bhe@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Resolves: bz1097904 https://bugzilla.redhat.com/show_bug.cgi?id=1097904 This is back port from upstream directly. commit 7f614cd1e052ebbddee7ea49c725dc75fee74a5a Author: HATAYAMA Daisuke Date: Wed Jul 3 15:02:15 2013 -0700 vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list Treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list. Formally, for each range [start, end], we set up the corresponding vmcore object in vmcore_list to [rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)]. This change affects layout of /proc/vmcore. The gaps generated by the rearrangement are newly made visible to applications as holes. Concretely, they are two ranges [rounddown(start, PAGE_SIZE), start] and [end, roundup(end, PAGE_SIZE)]. Suppose variable m points at a vmcore object in vmcore_list, and variable phdr points at the program header of PT_LOAD type the variable m corresponds to. Then, pictorially: m->offset +---------------+ | hole | phdr->p_offset = +---------------+ m->offset + (paddr - start) | |\ | kernel memory | phdr->p_memsz | |/ +---------------+ | hole | m->offset + m->size +---------------+ where m->offset and m->offset + m->size are always page-size aligned. Signed-off-by: HATAYAMA Daisuke Acked-by: Vivek Goyal Cc: KOSAKI Motohiro Cc: Atsushi Kumagai Cc: Lisa Mitchell Cc: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Baoquan He --- fs/proc/vmcore.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index f7b9aa1..2850906 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -402,20 +402,27 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, phdr_ptr->p_memsz; /* Note sections */ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 paddr, start, end, size; + if (phdr_ptr->p_type != PT_LOAD) continue; + paddr = phdr_ptr->p_offset; + start = rounddown(paddr, PAGE_SIZE); + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); + size = end - start; + /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; + new->paddr = start; + new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset. */ - phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + phdr_ptr->p_offset = vmcore_off + (paddr - start); + vmcore_off = vmcore_off + size; } return 0; } @@ -438,20 +445,27 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, phdr_ptr->p_memsz; /* Note sections */ for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 paddr, start, end, size; + if (phdr_ptr->p_type != PT_LOAD) continue; + paddr = phdr_ptr->p_offset; + start = rounddown(paddr, PAGE_SIZE); + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); + size = end - start; + /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; + new->paddr = start; + new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset */ - phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + phdr_ptr->p_offset = vmcore_off + (paddr - start); + vmcore_off = vmcore_off + size; } return 0; } -- 2.1.0